1. Field of the Invention
This invention relates to improvements in wire securing members, and more particularly, to improvements in serrated type wire securing members to present enhanced physical and electrical characteristics.
2. Description of the Prior Art
In making electrical connections between two or more wires, a "splice" apparatus is often employed. Also, in establishing a connection between one or more wires, and, for example, a terminal post or other connection to electrical circuitry, a so called "terminal" is employed. Such terminals typically employ a planar section which is formed by a crimping tool to encircle the wire or wires to be connected. Upon further crimping pressure by the crimping tool, the wires are firmly secured in a barrel portion formed by the bent planar member about the wires. A tongue portion, often of donut shape, extends cutwardly from the planar member to be attached to a bolt or terminal post or other circuitry means. The splice, on the other hand, is of similar construction to the terminal, except that the donut or circuitry connection portion is generally omitted. Usually, two or more wires are located adjacent the planar member, and the planar member is bent into a barrel shape and crimped by a similar crimping tool to secure the wires therein.
It has been known that the inclusion of multiple serrations or ridges upon the planar portion of such splice or terminal which is crimped to form the wire securing barrel greatly enhances the physical and electrical connections made to the wire or wires desired to be connected to the terminal or splice. In operation, because of the serrations, generally the insulation from the wires to be connected is not required to be removed. As the planar portion is crimped about the wire, the protrusions or ridges of the serrations actually penetrate the insulation, tearing it from the conductor of the wire. Upon further application of the crimping force, the metal or conductor material of the wire is forced or squeezed into the grooves or serrations between the ridges.
In forming a splice connection between two or more wires, typically the wires to be spliced are placed within the splice apparatus, and are blocked at their free ends by a shear or cutting blade which trims off the excess wire. The planar section of the splice is then mechanically crimped into a barrel form around the wires, and a crimping pressure applied to force the serrations through the insulation and the conductor material into the serrations, as above mentioned. Because of the blocked end, however, a transverse force which increases with distance from the blocked end exists within the wire material along the length of the wire away from the blocked end by virtue of the tremendous crimping forces applied. This transverse force causes the conductor material of the wire to actually move in a direction away from the blocked end. This, in turn, exerts a tremendous force upon the walls of the ridges defining the serrations, and in many cases, actually bends the serration walls over, especially in the ridges farthest away from the blocked end.
Additionally, because of the transverse direction of the flow of conductor material, the conductor material is not effectively forced to the floors of the serrations away from the blocked end. This results in relatively poor electrical connection at these serrations.
Another disadvantage of the splices of the prior art is that ordinarily only a very narrow range of wire sizes can be accommodated by a particular size of splice member. For example, if too small a wire is attempted to be crimped within a splice member, the ridges or ribs of the serration can actually cut completely through the conductor as well as the insulation thereof, destroying an electrical connection which might otherwise be made. On the other hand, if too large a wire were attempted to be connected to the splice member, the ridges of the serrations in some cases may not penetrate through the thick insulation layer of the wire.
Since the terminal connectors embody as a part thereof a member or portion similar to the splice member above described, which functions in essentially the same manner, except that it can be used with one or more wires, the terminal members of the prior art suffer the same disadvantages of the splice members. As used hereinafter, it will be understood tht the word "terminal" includes both terminal members and slice members as above described.